package com.century.sjt.util;

import java.security.MessageDigest;

/** 
 * 对外提供getMD5(String)方法 
 * @author randyjia 
 * 
 */  
public class MD5 {  
      
//    public static String getMD5(String val) throws NoSuchAlgorithmException{
//        MessageDigest md5 = MessageDigest.getInstance("MD5");
//        md5.update(val.getBytes());
//        byte[] m = md5.digest();//加密
//        return getString(m);
//}
    private static String getString(byte[] b){
        StringBuffer sb = new StringBuffer();
         for(int i = 0; i < b.length; i ++){  
          sb.append(b[i]);  
         }  
         return sb.toString();  
}
    public final static String MD5(String s) {
        char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
        try {
            byte[] btInput = s.getBytes();
            // 获得MD5摘要算法的 MessageDigest 对象
            MessageDigest mdInst = MessageDigest.getInstance("MD5");
            // 使用指定的字节更新摘要
            mdInst.update(btInput);
            // 获得密文
            byte[] md = mdInst.digest();
            // 把密文转换成十六进制的字符串形式
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}  